In the most severe cases, alcohol poisoning can lead to coma, brain damage and death.

When to seek medical help

If you suspect alcohol poisoning, dial 999 immediately to request an ambulance. While you're waiting:

try to keep them sitting up and awake

give them water if they can drink it

if they've passed out, lie them on their side in the recovery position and check they're breathing properly

keep them warm

stay with them and monitor their symptoms

Never leave a person alone to 'sleep it off'. The level of alcohol in a person's blood can continue to rise for up to 30-40 minutes after their last drink. This can cause their symptoms to suddenly become much more severe.

You also shouldn't give them coffee or any more alcohol, put them under a cold shower or walk them around. These won't help someone 'sober up' and may even be dangerous.

How alcohol poisoning is treated in hospital

In hospital, the person will be carefully monitored until the alcohol has left their system. If treatment is required, this may include:

inserting a tube into their mouth and windpipe (intubation) – to open the airway, remove any blockages and help with breathing

fitting an intravenous drip, which goes directly into a vein – to top up their water, blood sugar and vitamin levels

fitting a catheter (thin tube) to their bladder – to drain urine straight into a bag so they don't wet themselves

How alcohol poisoning occurs

Every time you drink alcohol, your liver has to filter it out of your blood. Alcohol is absorbed quickly into your body (much quicker than food), but the body can only process around one unit of alcohol an hour.

If you drink a lot of alcohol over a short space of time, such as on a night out, your body won't have time to process it all. Alcohol poisoning can also occur if a person drinks household products that contain alcohol – children sometimes drink these by accident.

The amount of alcohol in your bloodstream – known as your blood alcohol concentration (BAC) – will rise.

The effects of alcohol

Around 1-2 units

your heart rate will speed up and your blood vessels will expand

you get the warm, sociable feeling associated with moderate drinking

Around 4-6 units

your decision making and judgement will start to be affected, making you lose your inhibitions and become more reckless

the cells in your nervous system will start to be affected, making you feel lightheaded

your co-ordination will be affected and your reaction time may be slower

Around 8-9 units

your reaction times will be much slower

your speech will be slurred

your vision will begin to lose focus

your liver won't be able to remove all of the alcohol overnight, so it's likely you'll wake up with a hangover

At this stage you should seriously consider not drinking any more alcohol.

If you do:

Around 10-12 units

your co-ordination will be seriously impaired, placing you at high risk of having an accident

you may stagger around or feel unstable on your feet

you'll feel drowsy or dizzy

the amount of alcohol in your body will begin to reach toxic (poisonous) levels

you may need to go to the toilet more often as your body attempts to quickly pass the alcohol out of your body in your urine

you'll be dehydrated in the morning, and probably have a severe headache

the excess alcohol in your system may upset your digestive system, leading to nausea, vomiting, diarrhoea or indigestion

More than 12 units

you're at high risk of developing alcohol poisoning, particularly if you're drinking lots of units in a short space of time

the alcohol can begin to interfere with the automatic functions of your body, such as your breathing, heart rate and gag reflex

you're at risk of losing consciousness

Recommended alcohol limits

If you drink most weeks, to reduce your risk of harming your health:

men and women are advised not to regularly drink more than 14 units a week

spread your drinking over three days or more if you drink as much as 14 units a week